Method for producing cycloolefin polymers

ABSTRACT

The invention relates to a method for producing a cycloolefin copolymer by polymerization of 0.1-99.0 wt %, with respect to the total amount of monomers, of at least one polycyclic, 0-99.9 wt. %, with respect to the total amount of monomers, of at least one moncyclic olefin, and 0.1-99.9 wt. %, with respect to the total amount of monomers, of at least one acyclic 1-olefin, in the presence of a catalyst system consisting of at least one cocatalyst and at least one metallocene.

The invention relates to a process for preparing cycloolefin copolymershaving high molar masses.

It is known from the literature that cycloolefin homopolymers andcopolymers can be prepared using metallocene-aluminoxane catalystsystems (EP-A-283 164, EP-A-407 870). The polymerization of thecycloolefins proceeds here with retention of the rings and can becarried out in solvents or in bulk. As solvents, it is possible to usehydrocarbons.

EP 610 851 describes the preparation of cycloolefin polymers usingsuitable metallocene catalysts. EP 544 308 describes metallocenecatalysts which are suitable for the polymerization of α-olefins.

Cycloolefin copolymers can be prepared with a high cycloolefin contentand then have a high glass transition temperature. This is associatedwith a high heat distortion resistance, which is why these polymers aresuitable for use as thermoplastic molding compositions. Cycloolefincopolymers having a low cycloolefin content have a low glass transitiontemperature. At use temperature, they have a high ductility and can haveelastomeric properties.

It is found that cycloolefin copolymers prepared by means of metallocenetechnology have a relatively low mass average molar mass. In addition,the use of ethylene as comonomer frequently results in formation ofpartially crystalline ethylene polymers as by-products which cansignificantly impair the transparency of the cycloolefin copolymers.

It is an object of the present invention to provide a process forpreparing cycloolefin copolymers having a relatively high mass averagemolecular weight together with high transparency and excellentmechanical properties.

The object of the present invention has been achieved by a process forpreparing a cycloolefin copolymer by polymerization of from 0.1 to 99.9%by weight, based on the total amount of monomers, of at least onepolycyclic olefin, from 0 to 99.9% by weight, based on the total amountof monomers, of at least one monocyclic olefin and from 0.1 to 99.9% byweight, based on the total amount of monomers, of at least one acyclic1-olefin in the presence of a catalyst system.

The polymerization is carried out in the liquid cycloolefin itself or incycloolefin solution, with the pressure advantageously being above 1bar.

The catalyst system used in the process of the invention comprises atleast one metallocene of the formula I

where

M¹ is a metal of groups 3 to 10 or of the lanthanide series of thePeriodic Table of the Elements,

R¹ are identical or different and are each a cyclopentadienyl groupwhich may be substituted or an indenyl group which may be substitutedand partially hydrogenated,

R² is a single- or multi-membered bridge which links the radicals R¹ andcomprises at least one boron atom or at least one atom of group 14 ofthe Periodic Table of the Elements and may, if desired, comprise one ormore sulfur or oxygen atoms and can, if desired, form a fused ringsystem together with R¹,

R³ is an anionic or nonionic ligand, where n=0, 1, 2, 3 or 4 dependingon the valence of M.

The catalyst system to be used in the process of the invention canfurther comprise one or more cocatalysts.

The catalyst system to be used in the process of the invention is ahighly active catalyst for olefin polymerization. Preference is given tousing one metallocene and one cocatalyst. It is also possible to usemixtures of two or more metallocenes, particularly for preparing reactorblends or polyolefins having a broad or multimodal molar massdistribution.

The metallocene to be used in the process of the invention is preferablya compound of the formula I in which

M¹ is a metal of group 4 or the lanthanide series of the Periodic Tableof the Elements,

R¹ are identical or different and are each a cyclopentadienyl groupwhich may be substituted by one or more halogen atoms, one or moreC₁-C₄₀-groups such as C₁-C₁₀-alkyl groups which may be halogenated, oneor more C₆-C₂₀-aryl groups which may be halogenated, one or moreC₆-C₂₀-aryloxy groups, one or more C₂-C₁₂-alkenyl groups, one or moreC₇-C₄₀-arylalkyl groups, one or more C₇-C₄₀-alkylaryl groups, one ormore C₈-C₄₀-arylalkenyl groups, SiR⁴ ₃, NR⁴ ₂, Si(OR⁴)₃, Si(SR⁴)₃ or PR⁴₂, where R⁴ are identical or different and are each a halogen atom, aC₁-C₁₀-alkyl group or a C₆-C₁₀-aryl group or form a ring system, or anindenyl group which may be substituted by one or more halogen atoms, oneor more C₁-C₄₀-groups such as C₁-C₁₀-alkyl groups which may behalogenated, one or more C₆-C₂₀-aryl groups which may be halogenated,one or more C₆-C₂₀-aryloxy groups, one or more C₂-C₁₂-alkenyl groups,one or more C₇-C₄₀-arylalkyl groups, one or more C₇-C₄₀-alkylarylgroups, one or more C₈-C₄₀-arylalkenyl groups, SiR⁴ ₃, NR⁴ ₂, Si(OR⁴)₃,Si(SR⁴)₃ or PR⁴ ₂, where R⁴ are identical or different and are each ahalogen atom, a C₁-C₁₀-alkyl group or a C₆-C₁₀-aryl group or form a ringsystem, where the indenyl group can also be partially hydrogenated andone of the structures R¹ must bear a substituent,

R² is a single- or multi-membered bridge which links the groups R¹ andis preferably

 ═BR⁵,═AIR⁵, -Ge-, -Sn-, -O-, -S-, ═SO, ═SO₂, ═NR⁵, ═CO, ═PR or ═P(O)R⁵,

 where R⁵ are identical or different and are each a hydrogen atom, ahalogen atom, a C₁-C₄₀-group such as a C₁-C₁₀-alkyl group which may behalogenated, a C₆-C₂₀-aryl group which may be halogenated, aC₆-C₂₀-aryloxy group, a C₂-C₁₂-alkenyl group, a C₇-C₄₀-arylalkyl group,a C₇-C₄₀-alkylaryl group, a C₈-C₄₀-arylalkenyl group, SiR⁶ ₃, NR⁶ ₂,Si(OR⁶)₃ or PR⁶ ₃, where R⁶ are identical or different and are each ahalogen atom, a C₁-C₁₀-alkyl group or a C₆-C₁₀-aryl group or form a ringsystem, and

M² is silicon, germanium or tin,

R³ are identical or different and are each a hydrogen atom, aC₁-C₄₀group such as a C₁-C₁₀-alkyl group, a C₁-C₁₀-alkoxy group, aC₆-C₁₀-aryl group, a C₆-C₂₅-aryloxy group, a C₂-C₁₀-alkenyl group, aC₇-C₄₀-arylalkyl group or a C₇-C₄₀-arylalkenyl group, an OH group, ahalogen atom or NR⁷ ₂, where R⁷ is a halogen atom, a C₁-C₁₀-alkyl groupor a C₆-C₁₀-aryl group, or R³ together with the atoms connecting themform a ring system, where n=1 or 2.

The metallocene to be used in the process of the invention isparticularly preferably a compound of the formula II

where

M¹ is titanium, zirconium or hafnium,

R¹ is an indenyl group or a 4,5,6,7-tetrahydroindenyl group which issubstituted in positions 2 and 3 exclusively by hydrogen atoms and inpositions 4, 5, 6 and 7 may bear further substituents such as one ormore halogen atoms and/or one or more C₁-C₁₀-groups in place ofhydrogen,

R¹ is a cyclopentadienyl group which is substituted in position 3 by aC₂-C₄₀-group such as a C₂-C₁₀-alkyl group which may be halogenated, aC₆-C₂₀-aryl group which may be halogenated, a C₆-C₂₀-aryloxy group, aC₂-C₁₂-alkenyl group, a C₇-C₄₀-arylalkyl group, a C₇-C₄₀-alkylarylgroup, a C₈-C₄₀-arylalkenyl group, SiR⁴ ₃, NR⁴ ₂, SIR(OR⁴)₃, Si(SR⁴)₃ orPR⁴ ₂, where R⁴ are identical or different and are each a halogen atom,a C₁-C₁₀-alkyl group or a C₆-C₁₀-aryl group or form a ring system, andin the further positions 2, 4 and 5 may bear further substituents suchas one or more C₁-C₁₀-groups or one or more halogen atoms in place ofhydrogen,

R² is a single-, two- or three-membered bridge which links R¹ and R^(1′)in each case via position 1 and is preferably

 where R⁵ are identical or different and are each a hydrogen atom, aC₁-C₄₀-group such as a C₁-C₁₀-alkyl group which may be halogenated, aC₆-C₂₀-aryl group which may be halogenated, a C₆-C₂₀-aryloxy group, aC₂-C₁₂-alkenyl group, a C₇-C₄₀-arylalkyl group, a C₇-C₄₀-alkylaryl groupor a C₈-C₄₀-arylalkenyl group, where o=1, 2 or 3,

M² is silicon,

R³ are identical or different and are each a hydrogen atom, aC₁-C₄₀-group such as a C₁-C₁₀-alkyl group, a C₁-C₁₀-alkoxy group, aC₆-C₁₀-aryl group, a C₆-C₂₅-aryloxy group, a C₂-C₁₀-alkenyl group, aC₇-C₄₀-arylalkyl group or a C₇-C₄₀-arylalkenyl group, an OH group, ahalogen atom or NR⁷ ₂, where R⁷ is a halogen atom, a C₁-C₁₀-alkyl groupor a C₆-C₁₀-aryl group, or R³ together with the atoms connecting themform a ring system, where n=2.

The metallocene to be used in the process of the invention is veryparticularly preferably a compound of the formula II in which

M¹ is zirconium,

R¹ is an indenyl group which bears no substituents in place of thehydrogen atoms,

R^(1′) is a cyclopentadienyl group which is substituted in position 3 bya C₂-C₁₀-alkyl group such as ethyl, propyl, isopropyl, tert-butyl orn-butyl, by a C₆-C₂₀-aryl group, a C₇-C₂₀-arylalkyl group, aC₇-C₄₀-alkylaryl group, SiR⁴ ₃, NR⁴ ₂, Si(OR⁴)₃, Si(SR⁴)₃ or PR⁴ ₂,where R⁴ are identical or different and are each a halogen atom, aC₁-C₄₀-alkyl group or a C₆-C₁₀-aryl group or form a ring system, and inthe further positions 2, 4 and 5 bears no substituents in place of thehydrogen atoms,

R² is a single-, two- or three-membered bridge which links R¹ and R^(1′)in each case via position 1 and is preferably

 where R⁵ are identical or different and are each a hydrogen atom, aC₁-C₄₀-group such as a C₁-C₁₀-alkyl group which may be halogenated, aC₆-C₂₀-aryl group which may be halogenated, a C₆-C₂₀-aryloxy group, aC₂-C₁₂-alkenyl group, a C₇-C₄₀-arylalkyl group, a C₇-C₄₀-alkylaryl groupor a C₈-C₄₀-arylalkenyl group, where o=1, 2 or 3,

M² is silicon,

R³ are identical or different and are each a hydrogen atom, aC₁-C₄₀group such as a C₁-C₁₀-alkyl group, a C₁-C₁₀-alkoxy group, aC₆-C₁₀-aryl group, a C₆-C₂₅-aryloxy group, a C₂-C₁₀-alkenyl group, aC₇-C₄₀-arylalkyl group or a C₇-C₄₀-arylalkenyl group, an OH group, ahalogen atom or NR⁷ ₂, where R⁷ is a halogen atom, a C₁-C₁₀-alkyl groupor a C₆-C₁₀-aryl group, or R³ together with the atoms connecting themform a ring system, where n=2.

Examples of metallocenes to be used according to the invention are:

isopropylene(1-indenyl)(3-methylcyclopentadienyl)zirconium dichloride

diphenylmethylene(1-indenyl)(3-methylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(1-indenyl)(3-methylcyclopentadienyl)zirconiumdichloride

isopropylene(1-indenyl)(3-ethylcyclopentadienyl)zirconium dichloride

diphenylmethylene(1-indenyl)(3-ethylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(1-indenyl) (3-ethylcyclopentadienyl)zirconiumdichloride

isopropylene(1-indenyl)(3-isopropylcyclopentadienyl)zirconium dichloride

diphenylmethylene(1-indenyl)(3-isopropylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(1-indenyl)(3-isopropylcyclopentadienyl)zirconiumdichloride

isopropylene(1-indenyl)(3-t-butylcyclopentadienyl)zirconium dichloride

diphenylmethylene(1-indenyl)(3-t-butylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(1-indenyl)(3-t-butylcyclopentadienyl)zirconiumdichloride

isopropylene(1-indenyl)(3-trimethylsilyicyclopentadienyl)zirconiumdichloride

diphenylmethylene(1-indenyl)(3-trimethylsilylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(1-indenyl)(3-trimethylsilylcyclopentadienyl)zirconiumdichloride

isopropylene(4,5,6,7-tetrahydro-1-indenyl)(3-trimethylsilylcyclopentadienyl)zirconiumdichloride

isopropylene(1-indenyl)(3,4-dimethylcyclopentadienyl)zirconiumdichloride

diphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(3-trimethylsilylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(3-trimethylsilylcyclopentadienyl)zirconiumdichloride

isopropylene(1-indenyl)(3,4-di-trimethylsilylcyclopentadienyl)zirconiumdichloride

diphenylmethylene(1-indenyl)(3,4-di-trimethylsilylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(1-indenyl)(3,4-di-trimethylsilylcyclopentadienyl)zirconiumdichloride

isopropylene(1-indenyl)(2,3-di-trimethylsilylcyclopentadienyl)zirconiumdichloride

diphenylmethylene(1-indenyl)(2,3-di-trimethylsilylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(1-indenyl)(2,3-di-trimethylsilylcyclopentadienyl)zirconium dichloride

isopropylene(1-indenyl)(3,4-dimethylcyclopentadienyl)zirconiumdichloride

diphenylmethylene(1-indenyl)(3,4-dimethylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(1-indenyl)(3,4-dimethylcyclopentadienyl)zirconiumdichloride

isopropylene(1-indenyl)(3,4-diethylcyclopentadienyl)zirconium dichloride

diphenylmethylene(1-indenyl)(3,4-diethylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(1-indenyl)(3,4-diethylcyclopentadienyl)zirconiumdichloride

isopropylene(1-indenyl)(3,4-diisopropylcyclopentadienyl)zirconiumdichloride

diphenylmethylene(1-indenyl)(3,4-diisopropylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(1-indenyl)(3,4-diisopropylcyclopentadienyl)zirconiumdichloride

isopropylene(1-indenyl)(3,4-di-t-butylcyclopentadienyl)zirconiumdichloride

diphenylmethylene(1-indenyl)(3,4-di-t-butylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(1-indenyl)(3,4-di-t-butylcyclopentadienyl)zirconiumdichloride

isopropylene(1-indenyl)(2,3-dimethylcyclopentadienyl)zirconiumdichloride

diphenylmethylene(1-indenyl)(2,3-dimethylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(1-indenyl)(2,3-dimethylcyclopentadienyl)zirconiumdichloride

isopropylene(1-indenyl)(2,3-diethylcyclopentadienyl)zirconium dichloride

diphenylmethylene(1-indenyl)(2,3-diethylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(1-indenyl)(2,3-diethylcyclopentadienyl)zirconiumdichloride

isopropylene(1-indenyl)(2,3-diisopropylcyclopentadienyl)zirconiumdichloride

diphenylmethylene(1-indenyl)(2,3-diisopropylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(1-indenyl)(2,3-diisopropylcyclopentadienyl)zirconiumdichloride

isopropylene(1-indenyl)(2,3-di-t-butylcyclopentadienyl)zirconiumdichloride

diphenylmethylene(1-indenyl)(2,3-di-t-butylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(1-indenyl)(2,3-di-t-butylcyclopentadienyl)zirconiumdichloride

isopropylene(1-indenyl)(tetramethylcyclopentadienyl)zirconium dichloride

diphenylmethylene(1-indenyl)(tetramethylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(1-indenyl)(tetramethylcyclopentadienyl)zirconiumdichloride

isopropylene(4,5,6,7-tetrahydro-1-indenyl)(3-methylcyclopentadienyl)zirconiumdichloride

diphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(3-methylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(3-methylcyclopentadienyl)zirconiumdichloride

isopropylene(4,5,6,7-tetrahydro-1-indenyl)(3-ethylcyclopentadienyl)zirconiumdichloride

diphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(3-ethylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(3-ethylcyclopentadienyl)zirconiumdichloride

isopropylene(4,5,6,7-tetrahydro-1-indenyl)(3-isopropylcyclopentadienyl)zirconiumdichloride

diphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(3-isopropylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(3-isopropylcyclopentadienyl)zirconiumdichloride

isopropylene(4,5,6,7-tetrahydro-1-indenyl)(3-t-butylcyclopentadienyl)zirconiumdichloride

diphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(3-t-butylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(3-t-butylcyclopentadienyl)zirconiumdichloride

isopropylene(4,5,6,7-tetrahydro-1-indenyl)(3,4-dimethylcyclopentadienyl)zirconiumdichloride

diphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(3,4-dimethylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(3,4-dimethylcyclopentadienyl)zirconiumdichloride

isopropylene(4,5,6,7-tetrahydro-1-indenyl)(3,4-diethylcyclopentadienyl)zirconiumdichloride

diphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(3,4-diethylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(3,4-diethylcyclopentadienyl)zirconiumdichloride

isopropylene(4,5,6,7-tetrahydro-1-indenyl)(3,4-diisopropylcyclopentadienyl)zirconiumdichloride

diphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(3,4-diisopropylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(3,4-diisopropylcyclopentadienyl)zirconiumdichloride

isopropylene(4,5,6,7-tetrahydro-1-indenyl)(3,4-di-t-butylcyclopentadienyl)zirconiumdichloride

diphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(3,4-di-t-butylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(3,4-di-t-butylcyclopentadienyl)zirconiumdichloride

isopropylene(4,5,6,7-tetrahydro-1-indenyl)(2,3-dimethylcyclopentadienyl)zirconiumdichloride

diphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(2,3-dimethylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(2,3-dimethylcyclopentadienyl)zirconiumdichloride

isopropylene(4,5,6,7-tetrahydro-1-indenyl)(2,3-dimethylcyclopentadienyl)zirconiumdichloride

diphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(2,3-diethylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(2,3-diethylcyclopentadienyl)zirconiumdichloride

isopropylene(4,5,6,7-tetrahydro-1-indenyl)(2,3-diisopropylcyclopentadienyl)zirconiumdichloride

diphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(2,3-diisopropylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(2,3-diisopropylcyclopentadienyl)zirconiumdichloride

isopropylene(4,5,6,7-tetrahydro-1-indenyl)(2,3-di-t-butylcyclopentadienyl)zirconiumdichloride

diphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(2,3-di-t-butylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(2,3-di-t-butylcyclopentadienyl)zirconiumdichloride

isopropylene(4,5,6,7-tetrahydro-1-indenyl)(tetramethylcyclopentadienyl)zirconiumdichloride

diphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(tetramethylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(tetramethylcyclopentadienyl)zirconiumdichloride

Particular preference is given to:

isopropylene(1-indenyl)(3-isopropylcyclopentadienyl)zirconium dichloride

diphenylmethylene(1-indenyl)(3-isopropylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(1-indenyl)(3-isopropylcyclopentadienyl)zirconiumdichloride

isopropylene(1-indenyl)(3-t-butylcyclopentadienyl)zirconium dichloride

diphenylmethylene(1-indenyl)(3-t-butylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(1-indenyl)(3-t-butylcyclopentadienyl)zirconiumdichloride

isopropylene(4,5,6,7-tetrahydro-1-indenyl)(3-isopropylcyclopentadienyl)zirconiumdichloride

diphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(3-isopropylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(3-isopropylcyclopentadienyl)zirconiumdichloride

isopropylene(1-indenyl)(3-trimethylsilylcyclopentadienyl)zirconiumdichloride

diphenylmethylene(1-indenyl)(3-trimethylsilylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(1-indenyl)(3-trimethylsilylcyclopentadienyl)zirconiumdichloride

isopropylene(4,5,6,7-tetrahydro-1-indenyl)(3-t-butylcyclopentadienyl)zirconiumdichloride

diphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(3-t-butylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(3-t-butylcyclopentadienyl)zirconiumdichloride

isopropylene(4,5,6,7-tetrahydro-1-indenyl)(3-trimethylsilylcyclopentadienyl)zirconiumdichloride

diphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(3-trimethylsilylcyclopentadienyl)zirconiumdichloride

methylphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(3-trimethylsilylcyclopentadienyl)zirconiumdichloride

In the process of the invention, the cocatalyst used is preferably analuminoxane which preferably has the formula IIIa for the linear typeand/or the formula IIIb for the cyclic type,

where, in the formulae IIIa and IIIb, the radicals R⁸ are identical ordifferent and are each a C₁-C₆-alkyl group, a C₆-C₁₈-aryl group, benzylor hydrogen and n is an integer from 2 to 50, preferably from 10 to 35.Preferably, the radicals R⁸ are identical and are methyl, isobutyl,phenyl or benzyl, particularly preferably methyl.

If the radicals R⁸ are different, they are preferably methyl andhydrogen or alternatively methyl and isobutyl, with hydrogen or isobutylpreferably being present in a proportion by number of from 0.01 to 40%(of the radicals R⁸).

The aluminoxane can be prepared in various ways by known methods. One ofthe methods is, for example, reacting an aluminum hydrocarbon compoundand/or a hydridoaluminum hydrocarbon compound with water (gaseous,solid, liquid or bound, for example as water of crystallization) in aninert solvent (such as toluene). To prepare an aluminoxane havingdifferent alkyl groups R⁸, two different trialkylaluminums (AIR₃+AIR′₃)corresponding to the desired composition are reacted with water (S.Pasynkiewicz, Polyhedron 9 (1990) 429, EP-A-302 424). The precisethree-dimensional structure of the aluminoxanes is not known.

Regardless of the method of preparation, all aluminoxane solutions havein common a varying content of unreacted aluminum starting compoundwhich is present in free form or as adduct.

It is also possible to apply the aluminoxane to a support and then touse it as a suspension in supported form. A number of methods ofapplying the aluminoxane to a support are known (EP-A-578 838). Silicagel can function as support.

It is possible to preactivate the metallocene to be used in the processof the invention by means of a cocatalyst, in particular an aluminoxane,prior to use in the polymerization reaction. This significantlyincreases the polymerization activity.

The preactivation of the transition metal compound is carried out insolution. Here, the metallocene is preferably dissolved in a solution ofthe aluminoxane in an inert hydrocarbon. Suitable inert hydrocarbons arealiphatic or aromatic hydrocarbons. Preference is given to usingtoluene.

The concentration of the aluminoxane in the solution is in the rangefrom about 1% by weight to the saturation limit, preferably from 5 to30% by weight, in each case based on the total solution. The metallocenecan be used in the same concentration, but it is preferably used in anamount of from 10⁻⁴ to 1 mol per mol of aluminoxane. The preactivationtime is from 5 minutes to 60 hours, preferably from 5 to 60 minutes. Thepreactivation is carried out at a temperature of from −78 to 100° C.,preferably from 0 to 70° C.

A prepolymerization can be carried out with the aid of the metallocene.For the prepolymerization, preference is given to using the (or one ofthe) olefin(s) used in the polymerization.

The metallocene can also be applied to a support. Suitable supports are,for example, silica gels, aluminum oxides, solid aluminoxane or otherinorganic support materials. A polyolefin powder in finely divided formis also a suitable support material.

A further possible embodiment of the process of the invention comprisesusing a salt-like compound of the formula R_(x)NH_(4−x)BR′₄ or of theformula R₃PHBR′₄ as cocatalyst in place of or in addition to analuminoxane. Here, x=1, 2 or 3, R=alkyl or aryl, identical or different,and R′=aryl which may be fluorinated or partially fluorinated. In thiscase, the catalyst comprises the reaction product of a metallocene withone of the compounds mentioned (EP-A-277 004).

If solvents are added to the reaction mixture, they are customary inertsolvents such as aliphatic or cycloaliphatic hydrocarbons, petroleumfractions or hydrogenated diesel oil fractions or toluene.

The metallocenes are preferably used in the form of their racemates. Themetallocene is preferably employed in a concentration, based on thetransition metal, of from 10⁻¹ to 10⁻⁸ mol, preferably from 10⁻² to 10⁻⁷mol, particularly preferably from 10⁻³ to 10⁻⁷ mol, of transition metalper dm³ of reactor volume. The aluminoxane is used in a concentration offrom 10⁻⁴ to 10⁻¹ mol, preferably from 10⁻⁴ to 2×10⁻² mol, per dm³ ofreactor volume, based on the aluminum content. However, higherconcentrations are also possible in principle.

The invention provides a process for preparing a cycloolefin copolymerby polymerization of from 0.1 to 99.9% by weight, based on the totalamount of monomers, of at least one polycyclic olefin of the formula IV,V, V′, VI, VII, VIII or IX

where R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵, and R¹⁶ are identical ordifferent and are each a hydrogen atom or a hydrocarbon radical, whereidentically numbered radicals in the various formulae can also havedifferent meanings, from 0 to 99.9% by weight, based on the total amountof the monomers, of at least one monocyclic olefin of the formula X

where q is from 2 to 10, and from 0.1 to 99.9% by weight, based on thetotal amount of monomers, of at least one acyclic 1-olefin of theformula XI

where R¹⁷, R¹⁸, R¹⁹ and R²⁰ are identical or different and are each ahydrogen atom or a hydrocarbon radical, preferably a C₆-C₁₀-aryl radicalor a C₁-C₈-alkyl radical, at temperatures of from −78 to 150° C., inparticular from 0 to 100° C., and a pressure of from 0.01 to 64 bar.

Preference is given to cycloolefins of the formula IV or VI in which R⁹,R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵ and R¹⁶ are identical or different and areeach a hydrogen atom or a hydrocarbon radical, in particular aC₆-C₁₀-aryl radical or a C₁-C₈-alkyl radical, where identically numberedradicals in the various formulae can have different meanings.

If desired, one or more monocyclic olefins of the formula X are used forthe polymerization.

Preference is also given to an acyclic olefin of the formula XI in whichR¹⁷ R¹⁸, R¹⁹ and R²⁰ are identical or different and are each a hydrogenatom or a hydrocarbon radical, preferably a C₆-C₁₀-aryl radical or aC₁-C₈-alkyl radical, for example ethylene or propylene.

In particular, copolymers of polycyclic olefins, preferably of theformulae IV and VI, with ethylene are prepared.

Particularly preferred polycyclic olefins are norbornene andtetracyclododecene; these may be substituted by C₁-C₆-alkyl. They arepreferably copolymerized with ethylene. Very particular preference isgiven to ethylene-norbornene copolymers and ethylene-tetracyclododecenecopolymers.

The polycyclic olefin is used in an amount of from 0.1 to 99.9% byweight and the monocyclic olefin is used in an amount of from 0 to 99.9%by weight, in each case based on the total amount of monomers.

The concentration of the acyclic olefin used is determined by itssolubility in the reaction medium at the given pressure and the giventemperature.

For the purposes of the present invention, polycyclic olefins,monocyclic olefins and acyclic olefins include mixtures of two or moreolefins of the respective type. This means that it is possible toprepare not only polycyclic bicopolymers but also tercopolymers andmulticopolymers by the process of the invention. Copolymers ofmonocyclic olefins and acyclic olefins can also be obtained by theprocess described.

Among the monocyclic olefins, preference is given to cyclopentene, whichmay be substituted.

The process of the invention is preferably carried out at temperaturesof from −78 to 150° C., in particular from 0 to 100° C., and a pressureof from 0.01 to 64 bar.

In the preparation of copolymers, the molar ratio of the polycyclicolefin to the open-chain olefin used can be varied within a wide range.Preference is given to using molar ratios of cycloolefin to open-chainolefin of from 3:1 to 200:1. Selection of the polymerizationtemperature, the concentration of the catalyst components and the molarratio or pressure of the gaseous, open-chain olefin enables theproportion of comonomer incorporated to be controlled almost as desired.Preference is given to incorporated proportions of the cyclic componentsof from 5 to 80 mol %, particularly preferably from 15 to 60 mol % andvery particularly preferably from 35 to 55 mol %.

The cycloolefin copolymers prepared by the process of the invention haveglass transition temperatures of from −50 to 220° C. Preference is givento glass transition temperatures of from 0 to 180° C., particularlypreferably from 60 to 150° C.

The polymerization can also be carried out in a plurality of stages, sothat block copolymers can also be formed (DE-A-42 05 416).

The mean molar mass of the polymer formed can be controlled in a knownmanner by metering-in hydrogen, varying the catalyst concentration orvarying the temperature.

The cycloolefin copolymers prepared by the process of the invention havemass average molar masses M_(w) of from 1000 to 10,000,000 g/mol.Preference is given to mass average molar masses of from 10,000 to5,000,000 g/mol, particularly preferably from 50,000 to 1,200,000 g/mol.

The cycloolefin copolymers prepared by the process of the invention haveviscosity numbers of from 10 to 1000 ml/g, preference is given toviscosity numbers of from 30 to 500 ml/g, particularly preferably from50 to 300 ml/g.

Cycloolefin copolymers which have not been prepared by the process ofthe invention have a low molar mass and a low toughness, so that thesematerials are of little interest for commercial use.

It has now surprisingly been found that cycloolefin copolymers havingsignificantly higher molar masses can be prepared over a wide range ofglass transition temperatures by the process of the invention. Thecycloolefin copolymers prepared by the process of the invention have ahigher melting resistance and toughness and are therefore of particularinterest for commercial use.

The cycloolefin copolymers prepared by the process of the inventionsurprisingly have a high elongation at break.

The elongation at break R of the cycloolefin polymers prepared by theprocess of the invention has values of R≧−0.0375 T_(g)+12. Thecycloolefin copolymers prepared by the process of the inventionpreferably have values of R≧−0.0375 T_(g)+17. The cycloolefin copolymersprepared by the process of the invention particularly preferably havevalues of R≧−0.0375 T_(g)+22.

Owing to the high elongation at break which has surprisingly been found,the cycloolefin copolymers prepared by the process of the invention aredistinctly superior to those of the prior art.

In addition to excellent resistance to thermal and chemical influences,the moldings produced from cycloolefin copolymers prepared by theprocess of the invention have very good resistance to mechanicalstresses such as tensile, flexural and impact stresses. This means thatthe cycloolefin copolymers prepared by the process of the invention canbe used in a wide variety of applications.

As a rheological parameter which is easy to determine and is relateddirectly to the mechanical properties of plastics, the plateau modulusG′_(p) describes the excellent properties of the cycloolefin copolymersprepared by the process of the invention.

The elastic properties of polymer melts can be determined by avibrational experiment. Here, the storage modulus G′ is a measure of thedeformation energy which can be stored reversibly by the polymer. Atrelatively high applied frequencies, the storage modulus G′ goes througha rubber-elastic plateau (plateau zone) [Retting, W., H. H. Laun,Kunststoffphysik, Carl Hansen Verlag, 1991; Ferry, J. D., ViscoelasticProperties of Polymers, J. Wiley & Sons, 1980]. In the plateau zone, thevalue of the storage modulus is determined by the network of intermeshedpolymer molecules. In this region, the applied frequency is so high thatthe molecules can no longer slide off one another, so that the temporaryintermeshing points have the same effect as permanent crosslinkingpoints in chemically crosslinked polymers. The energy introduced istaken up only by the flexible chain segments between the intermeshingpoints. The storage modulus G′ in the region of the rubber-elasticplateau is defined as the plateau modulus G′_(p). The plateau modulusG′_(p) serves as a measure for the energy which can be taken up by thetemporary network.

The relationship between the plateau modulus and the mechanicalproperties of polymeric solids is comprehensively described in thespecialist literature. [Aharoni, S. M., Macromolecules 18, 2624 (1985);Mikar, A. G. et al., J. Chem. Phys. 88, 1337 (1988); Mikar, A. G. etal., J. Polym. Sci. B 27, 837 (1991); Wu, S., J. Polym. Sci 327, 723(1989); Wu, S., Polym. Int. 29, 229 (1992)].

It has surprisingly been found that the cycloolefin copolymers preparedby the process of the invention have a plateau modulus which is highcompared to conventional cycloolefin copolymers. The plateau modulus ofthe cycloolefin polymers prepared by the process of the inventionpreferably has values which obey the following relationship:

log G′ _(p)≧−0.0035T _(g)+6

The plateau modulus of the cycloolefin polymers prepared by the processof the invention particularly preferably has values which obey thefollowing relationship:

log G′ _(p)≧−0.0035T _(g)+6.03

The plateau modulus of the cycloolefin polymers prepared by the processof the invention very particularly preferably has values which obey thefollowing relationship:

log G′ _(p)≧−0.0035T _(g)+6.06

The polydispersity M_(w)/M_(n) of the copolymers has values of from 1.5to 3.5 and is therefore quite narrow. This results in a property profilewhich makes the copolymers particularly suitable for injection molding.It is also possible to obtain a polydispersity beyond the indicatedlimits by selection of the catalyst system. Apart from monomodaldistributions, cycloolefin copolymers having bimodal or multimodaldistributions can also be prepared by the process of the invention.

If catalyst systems which are not as specified in the process of theinvention are chosen, it is possible for ethylene polymers which reducethe transparency of the material to be formed in addition of thecycloolefin copolymers. In addition, the insolubility of these ethylenepolymers leads to formation of deposits during the process, whichdeposits interfere with the production process and require regularcleaning work.

It has now surprisingly been found that no ethylene polymers are formedwhen employing the catalyst system to be used in the process of theinvention. The process of the invention enables cycloolefin copolymersof high transparency to be prepared.

A particular advantage which has been found is the high effectiveness ofthe process of the invention in respect of the extremely high activityof the catalyst system. This enables significantly higher yields ofcycloolefin copolymers to be achieved by the process of the inventioncompared to processes which are not according to the invention. Thus,the process of the invention offers a considerable economic advantage interms of the catalyst costs.

Both in extrusion and in injection molding, neither decompositionreactions nor a decrease in viscosity have been found at temperatures of300° C.

The materials prepared according to the invention are particularlysuitable for producing moldings such as extruded parts (films, sheets,hoses, pipes, rods and fibers) or injection-molded articles of any shapeand size. Important properties of the materials of the invention aretheir transparency, their purity, the favorable mechanical properties,the low water absorption and the high barrier action against watervapor.

The index of refraction of the reaction products described in thefollowing examples determined using an Abbe refractometer and mixedlight is in the range from 1.520 to 1.555. Since the index of refractionis very close to that of crown glass (n=1.51), the products according tothe invention can be employed as a substitute for glass in variousapplications in the optical field, for example lenses, prisms, supportplates and films for optical data storage, for video disks, for compactdisks, as covering and focusing plates for solar cells, as covering andscattering plates for power optics, as optical waveguides in the form offibers or films. Owing to the property profile described, the materialsprepared according to the invention are of great interest in the fieldof medical technology. They are used as materials for catheters, bagsfor infusion solutions or dialysis fluid, for tubing, containers,implants and components of medical apparatus. In addition, they are usedin the form of injection-molded parts for containers, bottles, vials andsyringes for the storage, exchange or application of liquids. Theproperties of the cycloolefin copolymers prepared according to theinvention make them particularly suitable for use in the form of filmsfor the pharmaceutical, food and industrial sectors.

In impact-modified form, the materials prepared according to theinvention can also be used as structural materials in variousengineering areas (DE-A-42 13 219).

The polymers obtained according to the invention can also be used forproducing polymer blends. The blends can be produced in the melt or insolution. The blends have a property combination of the components whichis in each case favorable for particular applications. For blends withthe polymers of the invention, preference is given to using thefollowing polymers:

polyethylene, polypropylene, 1-(ethylene-propylene)copolymers,polybutylene, poly-(4methyl-1-pentene), polyisoprene, polyisobutylene,natural rubber, poly-1-(methyl methacrylate), further polymethacrylates,polyacrylates, (acrylate-methacrylate)copolymers, polystyrene,(styrene-acrylonitrile)copolymers, bisphenol A polycarbonate, furtherpolycarbonates, aromatic polyester carbonates, polyethyleneterephthalate, polybutylene terephthalate, amorphous polyarylates, nylon6, nylon 66, further polyamides, polyaramides, polyether ketones,polyoxymethylene, polyoxyethylene, polyurethanes, polysulfones,polyether sulfones, polyvinylidene fluoride.

Surfaces of workpieces and moldings produced from the cycloolefincopolymers of the invention can be modified by suitable methods such asfluorination, corona treatment, flame treatment and plasma treatment. Inthis way, properties such as adhesion or printability can be alteredwithout the requirement of the present invention being impaired.

The process of the invention gives transparent cycloolefin copolymershaving high molar masses at a particularly high catalyst activity.

The glass transition temperatures T_(g) reported in the followingexamples were determined by means of DSC (differential scanningcolorimetry) at a heating rate of 20° C./min. The viscosity numbers VNreported were determined in o-dichlorobenzene at 135° C. in accordancewith DIN 53728. The mass average molar mass and the polydispersity weredetermined by means of GPC.

Elongations at break and yield stresses were determined in a tensiletest in accordance with ISO 527, parts 1 and 2, at a strain rate of 50mm/min.

The rheological properties of the melt for determining the plateaumodulus were determined in a dynamic vibrational experiment using ashear-rate controlled instrument from Rheometrics having a plate-plategeometry at frequencies of from 10⁻¹ to 5×10²s⁻¹.

The measure employed for the catalyst activity is the yield of polymerper unit time and per mmol of metallocene:${Activity} = {\frac{{Polymer}\quad\lbrack g\rbrack}{{{Time}\quad\lbrack h\rbrack} \times {amount}\quad {of}\quad {{metallocene}\quad\lbrack{mmol}\rbrack}} = A}$

The invention is illustrated by the following examples:

EXAMPLES Example 1

600 cm³ of a 50% strength by weight solution of norbornene in tolueneare placed in a 1.5 dm³ autoclave which has previously been thoroughlypurged with ethene. The solution was saturated with ethene by multiplepressurization with ethene (6 bar). 10 cm³ of methylaluminoxane solutionin toluene (10% strength by weight methylaluminoxane solution having amolar mass of 1300 g/mol according to cryoscopic determination) weremetered in countercurrent into the reactor which had been prepared inthis way and the mixture was stirred for 30 minutes at 70° C. A solutionof 0.37 mg ofisopropylene(1-indenyl)(3-t-butylcyclopentadienyl)zirconium dichloridein 10 cm³ of methylaluminoxane solution in toluene was added afterpreactivation for 15 minutes. While stirring (750 rpm), polymerizationwas carried out for one hour, with the ethene pressure being maintainedat 6 bar by metering in further amounts.

After the end of the reaction time, the polymerization mixture wasdrained into a vessel and immediately introduced into 5 dm³ of acetone,stirred for 10 minutes and the precipitated product was subsequentlyfiltered off. The filter cake was washed alternately with three portionseach of 10% hydrochloric acid and acetone, the residue was slurried inacetone and filtered off again. The polymer which had been purified inthis way was dried at 80° C. under reduced pressure (0.2 bar) for 15hours.

This gave 40 g of colorless polymer which had a glass transitiontemperature of 139° C., a viscosity number of 185 ml/g, a weight averagemolar mass of 147,000 g/mol and a polydispersity of 1.9. The activity A*was 47,300 g/(mmol h).

Example 2

600 cm³ of a 50% strength by weight solution of norbornene in tolueneare placed in a 1.5 dm³ autoclave which has previously been thoroughlypurged with ethene. The solution was saturated with ethene by multiplepressurization with ethene (3 bar). 10 cm³ of methylaluminoxane solutionin toluene (10% strength by weight methylaluminoxane solution having amolar mass of 1300 g/mol according to cryoscopic determination) weremetered in countercurrent into the reactor which had been prepared inthis way and the mixture was stirred for 30 minutes at 70° C. A solutionof 0.61 mg ofisopropylene(1-indenyl)(3-t-butylcyclopentadienyl)zirconium dichloridein 10 cm³ of methylaluminoxane solution in toluene was added afterpreactivation for 15 minutes.

While stirring (750 rpm), polymerization was carried out for one hour,with the ethene pressure being maintained at 3 bar by metering infurther amounts.

After the end of the reaction time, the polymerization mixture wasdrained into a vessel and immediately introduced into 5 dm³ of acetone,stirred for 10 minutes and the precipitated product was subsequentlyfiltered off. The filter cake was washed alternately with three portionseach of 10% hydrochloric acid and acetone, the residue was slurried inacetone and filtered off again. The polymer which had been purified inthis way was dried at 80° C. under reduced pressure (0.2 bar) for 15hours. This gave 29 g of colorless polymer which had a glass transitiontemperature of 156° C., a viscosity number of 260 ml/g, a weight averagemolar mass of 271,000 g/mol and a polydispersity 2.5. The activity A was20,700 g/(mmol h).

Example 3

600 cm³ of a 50% strength by weight solution of norbornene in tolueneare placed in a 1.5 dm³ autoclave which has previously been thoroughlypurged with ethene. The solution was saturated with ethene by multiplepressurization with ethene (12 bar). 10 cm³ of methylaluminoxanesolution in toluene (10% strength by weight methylaluminoxane solutionhaving a molar mass of 1300 g/mol according to cryoscopic determination)were metered in countercurrent into the reactor which had been preparedin this way and the mixture was stirred for 30 minutes at 70° C. Asolution of 0.13 mg ofisopropylene(1-indenyl)(3-t-butylcyclopentadienyl)zirconium dichloridein 10 cm³ of methylaluminoxane solution in toluene was added afterpreactivation for 15 minutes.

While stirring (750 rpm), polymerization was carried out for one hour,with the ethene pressure being maintained at 12 bar by metering infurther amounts.

After the end of the reaction time, the polymerization mixture wasdrained into a vessel and immediately introduced into 5 dm³ of acetone,stirred for 10 minutes and the precipitated product was subsequentlyfiltered off. The filter cake was washed alternately with three portionseach of 10% hydrochloric acid and acetone, the residue was slurried inacetone and filtered off again. The polymer which had been purified inthis way was dried at 80° C. under reduced pressure (0.2 bar) for 15hours.

This gave 45 g of colorless polymer which had a glass transitiontemperature of 107° C., a viscosity number of 108 ml/g, a weight averagemolar mass of 82,000 g/mol and a polydispersity 1.8. The activity A was151,800 g/(mmol h).

Example 4

600 cm³ of a 50% strength by weight solution of norbomene in toluene areplaced in a 1.5 dm³ autoclave which has previously been thoroughlypurged with ethene. The solution was saturated with ethene by multiplepressurization with ethene (18 bar). 10 cm³ of methylaluminoxanesolution in toluene (10% strength by weight methylaluminoxane solutionhaving a molar mass of 1300 g/mol according to cryoscopic determination)were metered in countercurrent into the reactor which had been preparedin this way and the mixture was stirred for 30 minutes at 70° C. Asolution of 0.06 mg ofisopropylene(1-indenyl)(3-t-butylcyclopentadienyl)zirconium dichloridein 10 cm³ of methylaluminoxane solution in toluene was added afterpreactivation for 15 minutes.

While stirring (750 rpm), polymerization was carried out for one hour,with the ethene pressure being maintained at 18 bar by metering infurther amounts.

After the end of the reaction time, the polymerization mixture wasdrained into a vessel and immediately introduced into 5 dm³ of acetone,stirred for 10 minutes and the precipitated product was subsequentlyfiltered off. The filter cake was washed alternately with three portionseach of 10% hydrochloric acid and acetone, the residue was slurried inacetone and filtered off again. The polymer which had been purified inthis way was dried at 80° C. under reduced pressure (0.2 bar) for 15hours.

This gave 22 g of colorless polymer which had a glass transitiontemperature of 85° C., and a viscosity number of 94 ml/g. The activity Awas 160,800 g/(mmol h).

Examples 5 and 6

600 cm³ of a solution of norbornene in toluene are placed in a 1.5 ³autoclave which has previously been thoroughly purged with ethene. Thesolution was saturated with ethene by multiple pressurization withethene (18 bar). 5 cm³ of methylaluminoxane solution in toluene (10%strength by weight methylaluminoxane solution having a molar mass of 300g/mol according to cryoscopic determination) were metered incountercurrent into the reactor which had been prepared in this way andthe mixture was stirred for 30 minutes at 70° C. A solution ofisopropylene(1-indenyl)(3-t-butylcyclopentadienyl)zirconium dichloridein 5 cm³ of methylaluminoxane solution in toluene was added afterpreactivation for 15 minutes.

While stirring (750 rpm), polymerization was carried out for one hour,with the ethene pressure being maintained at 18 bar by metering infurther amounts.

After the end of the reaction time, the polymerization mixture wasdrained into a vessel and immediately introduced into 5 dm³ of acetone,stirred for 10 minutes and the precipitated product was subsequentlyfiltered off. The filter cake was washed alternately with three portionseach of 10% hydrochloric acid and acetone, the residue was slurried inacetone and filtered off again. The polymer which had been purified inthis way was dried at 80° C. under reduced pressure (0.2 bar) for 15hours.

This gave a colorless polymer. The further reaction conditions and thecharacteristic data of the polymer are summarized in Table 1.

TABLE 1 Monomer solution [% by Amount of weight catalyst Activity A*Yield T_(g) VM Ex. of norbornene] [mg] [g/mmol h] [g] [° C.] [ml/g] 5 500.05 92,100 10.5 83 80 6 30 0.09 238,800 49 46 64

Examples 7 and 15

400 cm³ of an 85% strength by weight solution of norbornene in tolueneare placed in a 1 dm³ autoclave which has previously been thoroughlypurged with ethane. The solution was saturated with ethene by multiplepressurization with ethene. 1 cm³ of methylaluminoxane solution intoluene (10% strength by weight methylaluminoxane solution having amolar mass of 1300 g/mol according to cryoscopic determination) weremetered in countercurrent into the reactor which had been prepared inthis way and the mixture was stirred for 30 minutes at 70° C. A solutionof 0.35 mg ofisopropylene(1-indenyl)(3-t-butylcyclopentadienyl)zirconium dichloridein 1 cm³ of methylaluminoxane solution in toluene was added afterpreactivation for 15 minutes.

Polymerization was carried out while stirring (800 rpm), with the ethenepressure being maintained by metering in further doses.

After the end of the reaction time, the polymerization mixture wasdrained into a vessel and immediately introduced into 5 dm³ of acetone,stirred for 10 minutes and the precipitated product was subsequentlyfiltered off. The filter cake was washed three times with acetone. Thepolymer obtained in this way was dried at 70° C. under reduced pressure(0.2 bar) for 15 hours. This gave a colorless polymer. The furtherreaction conditions and the characteristic data of the polymer aresummarized in Tables 2 and 3.

TABLE 2 Ethylene pressure Polymerization time Yield Activity A* Ex.[bar] [min] [g] [g/(mmol)] 7 20.9 10 19.2 144,000 8 14.9 15 18.1 90,5009 10.4 15 13 65,000 10 4.7 34 11.3 24,200 11 26.2 10 26 195,000 12 32.510 32 240,000 13 39.9 11 45.3 308,900 14 46.5 11 56 381,800 15 58 8 52487,500

TABLE 3 Ex. Tg [° C] VM [ml/g] M_(w) [g/mol] M_(w)/M_(n) 7 121 169222,000 1.6 8 135 226 322,000 1.5 9 145 307 422,000 1.7 10 155 — 793,0001.5 11 113 147 189,000 1.6 12 99.5 — 162,000 1.5 13 85 90 128,000 1.6 1476 92 104,000 1.6 15 57 84 83,000 1.6

Example 16

400 cm³ of a 42% strength by weight solution of norbornene in tolueneare placed in a 1 dm³ autoclave which has previously been purgedthoroughly with ethene. The solution was saturated with ethene bymultiple pressurization with ethene (53.6 bar). 1 cm³ ofmethylaluminoxane solution in toluene (10% strength by weightmethylaluminoxane solution having a molar mass of 1300 g/mol accordingto cryoscopic determination) was metered in countercurrent into thereactor which had been prepared in this way and the mixture was stirredfor 30 minutes at 70° C. A solution of 0.35 mg ofisopropylene(1-indenyl)(3-t-butylcyclopentadienyl)zirconium dichloridein 1 cm³ of methylaluminoxane solution in toluene was added afterpreactivation for 15 minutes.

While stirring (800 rpm), polymerization was carried out for 8 minutes,with the ethene pressure being maintained at 53.6 bar by metering infurther amounts.

After the end of the reaction time, the polymerization mixture wasdrained into a vessel and immediately introduced into 5 dm³ of acetone,stirred for 10 minutes and the precipitated product was subsequentlyfiltered off. The filter cake was washed three times with acetone. Thepolymer obtained in this way was dried at 70° C. under reduced pressure(0.2 bar) for 15 hours.

This gave 70 g of colorless polymer which had a glass transitiontemperature of 13° C., a viscosity number of 67 ml/g, a weight averagemolar mass of 57,000 g/mol and a polydispersity of 1.5. The activity A*was 656,300 g/(mmol h).

Comparative Examples 1 to 3

A solution of norbornene in toluene was placed in a 70 dm³ autoclavewhich had previously been purged thoroughly with ethene. The solutionwas saturated with ethene by multiple pressurization with ethene. 400cm³ of methylaluminoxane solution in toluene (10% strength by weightmethylaluminoxane solution having a molar mass of 1300 g/mol accordingto cryoscopic determination) were metered in countercurrent into thereactor which had been prepared in this way and the mixture was stirredfor 30 minutes at 70° C. After preactivation for 30 minutes, a solutionof isopropylene(cyclopentadienyl)(1-indenyl)zirconium dichloride in 300cm³ of methylaluminoxane solution in toluene was added.

While stirring (750 rpm), polymerization was carried out for one hour,with the ethene pressure being maintained by metering in furtheramounts.

After the end of the reaction time, the polymerization mixture wasdrained into a vessel and immediately introduced into 300 dm³ ofacetone, stirred for 30 minutes and the precipitated product wassubsequently filtered off. The filter cake was washed alternately withthree portions each of 10% hydrochloric acid and acetone, the residuewas slurried in acetone and filtered off again. The polymer which hadbeen purified in this way was dried at 80° C. under reduced pressure(0.2 bar) for 15 hours.

This gave a colorless polymer. The further reaction conditions and thecharacteristic data of the polymer are summarized in Tables 4 and 5.

TABLE 4 Monomer solution Monomer Ethylene [% by weight of solutionCatalyst pressure Yield Comp. Ex. norbornene] [dm³] [mg] [bar] [kg] 1 6030 100 20 8 2 40 50 160 22 7.4 3 40 32 100 20 7

TABLE 5 Activity A* T_(g) VM M_(w) Comp. Ex. [g/(mmol*h)] [° C.] [ml/g][bar] M_(w)/M_(n) 1 30,600 105 47 29,000 1.9 2 17,700 89 41 21,000 1.9 326,800 82 38 21,000 1.8

Comparative Examples 4 to 7

600 cm³ of a solution of norbornene in toluene are placed in a 1.5 dm³autoclave which has previously been purged thoroughly with ethene. Thesolution was saturated with ethene by multiple pressurization withethene (18 bar). 5 cm³of methylaluminoxane solution in toluene (10%strength by weight methylaluminoxane solution having a molar mass of1300 g/mol according to cryoscopic determination) were metered incountercurrent into the reactor which had been prepared in this way andthe mixture was stirred for 30 minutes at 70° C. A solution ofisopropylene(1-indenyl)(cyclopentadienyl)zirconium dichloride in 5 cm³of methylaluminoxane solution in toluene was added after preactivationfor 15 minutes.

While stirring (750 rpm), polymerization was carried out for one hour,with the ethene pressure being maintained by metering in furtheramounts.

After the end of the reaction time, the polymerization mixture wasdrained into a vessel and immediately introduced into 5 dm³ of acetone,stirred for 10 minutes and the precipitated product was subsequentlyfiltered off. The filter cake was washed alternately with three portionseach of 10% hydrochloric acid and acetone, the residue was slurried inacetone and filtered off again. The polymer which had been purified inthis way was dried at 80° C. under reduced pressure (0.2 bar) for 15hours.

This gave a colorless polymer. The further reaction conditions and thecharacteristic data of the polymer are summarized in Tables 6 and 7.

TABLE 6 Monomer solution Catalyst Ethylene pressure Comp. Ex. [% byweight of norbornene] [mg] [bar] 4 85 1.2 6 5 50 1.03 3 6 85 1.14 18 750 0.45 12

TABLE 7 Yield Activiy A T_(g) VN Comp. Ex. [kg] [g/(mmol h)] [° C.][ml/g] 4 44.8 14,300 184 67 5 33.6 12,500 181 81 6 99.8 33,500 140 78 755.6 36,400 122 64

Comparative Examples 8 to 11

A solution of 600 cm³ of norbomene in toluene was placed in a 1.5 dm³autoclave which had previously been purged thoroughly with ethene. Thesolution was saturated with ethene by multiple pressurization withethene (6 bar). 20 cm³ of methylaluminoxane solution in toluene (10%strength by weight methylaluminoxane solution having a molar mass of1300 g/mol according to cryoscopic determination) were metered incountercurrent into the reactor which had been prepared in this way andthe mixture was stirred for 30 minutes at 70° C. A solution ofdimethylsilylbis(1-indenyl)zirconium dichloride in 20 cm³ ofmethylaluminoxane solution in toluene was added after preactivation for15 minutes.

While stirring (750 rpm), polymerization was carried out for one hour,with the ethene pressure being maintained at 6 bar by metering infurther amounts.

After the end of the reaction time, the polymerization mixture wasdrained into a vessel and immediately introduced into 5 dm³ of acetone,stirred for 10 minutes and the precipitated product was subsequentlyfiltered off. The filter cake was washed alternately with three portionseach of 10% hydrochloric acid and acetone, the residue was slurried inacetone and filtered off again. The polymer which had been purified inthis way was dried at 80° C. under reduced pressure (0.2 bar) for 15hours.

This gave a colorless polymer. The further reaction conditions and thecharacteristic data of the polymer are summarized in Table 8.

TABLE 8 Monomer Amount Acti- solution [% of vity VN Comp by weight ofcatalyst Yield A* [g/ Tg m.p. [ml/ Ex. norbornene] [mg] [g] (mmol*h)] [°C.] [° C.] /g] 8 85 5 21 1884 122 122 45 9 85 5 20 1794 178 118 65 10 800.5 2.5 2243 138 120 45 11 30 60 180 1346 103 115 86

Comparative Examples 12 to 15

A solution of 600 cm³ of norbornene in toluene was placed in a 1.5 dm³autoclave which had previously been purged thoroughly with ethene. Thesolution was saturated with ethene by multiple pressurization withethene. 10 cm³ of methylaluminoxane solution in toluene (10% strength byweight methylaluminoxane solution having a molar mass of 1300 g/molaccording to cryoscopic determination) were metered in countercurrentinto the reactor which had been prepared in this way and the mixture wasstirred for 30 minutes at 70° C. A solution of 1.8 mg ofdimethylsilyl(cyclopentadienyl)(1-indenyl)zirconium dichloride in 10 cm³of methylaluminoxane solution in toluene was added after preactivationfor 15 minutes.

While stirring (750 rpm), polymerization was carried out for one hour,with the ethene pressure being maintained by metering in furtheramounts.

After the end of the reaction time, the polymerization mixture wasdrained into a vessel and immediately introduced into 5 dm³ of acetone,stirred for 10 minutes and the precipitated product was subsequentlyfiltered off. The filter cake was washed alternately with three portionseach of 10% hydrochloric acid and acetone, the residue was slurried inacetone and filtered off again. The polymer which had been purified inthis way was dried at 80° C. under reduced pressure (0.2 bar) for 15hours.

This gave a colorless polymer. The further reaction conditions and thecharacteristic data of the polymer are summarized in Table 9.

TABLE 9 Monomer Acti- solution [% Ethylene vity VN Comp by weight ofpressure Yield A* [g/ Tg [ml/ Ex. norbornene] [bar] [g] (mmol*h)] [° C.]/g] 12 85 6 9.4 2081 214 68 13 85 18 14.6 3232 161 130 14 50 18 33.97505 112 132 15 30 18 46.8 10,361 68 130

Examples 17 to 28

600 cm³ of a solution of norbornene in a solvent were placed in a 1.5dm³ autoclave which had previously been purged thoroughly with ethene.The solution was saturated with ethene by multiple pressurization withethene. A solution of methylaluminoxane in toluene (10% strength byweight methylaluminoxane solution having a molar mass of 1300 g/molaccording to cryoscopic determination) was metered in countercurrentinto the reactor which had been prepared in this way and the mixture wasstirred for 30 minutes at 70° C. A solution of the metallocene in amethylaluminoxane solution in toluene was added after preactivation for15 minutes.

While stirring (750 rpm), polymerization was carried out for one hour,with the ethene pressure being maintained by metering in furtheramounts.

After the end of the reaction time, the polymerization mixture wasdrained into a vessel and immediately introduced into 5 dm³of acetone,stirred for 10 minutes and the precipitated product was subsequentlyfiltered off. The filter cake was washed alternately with three portionseach of 10% hydrochloric acid and acetone, the residue was slurried inacetone and filtered off again. The polymer which had been purified inthis way was dried at 80° C. under reduced pressure (0.2 bar) for 15hours.

This gave a colorless polymer. The further reaction conditions and thecharacteristic data of the polymer as summarized in Tables 10 and 11.

TABLE 10 Methyl- Methylalumi Eth- Monomer alumin- noxane ene Ex-solution [% oxane Amount of solution for pres- am- by weight of solutionmetallo- metallocene sure ple norbornene] Solvent [ml] cene [mg] [ml][bar] 17 50 toluene 10 0.06 10 18 18 30 toluene 5 0.09 5 18 19 50toluene 5 0.15 5 18 20 50 toluene 10 0.08 10 6 21 50 toluene 10 0.04 1018 22 50 toluene 10 0.6 10 6 23 50 decalin 5 0.16 5 18 24 50 decalin 20.67 2 18 25 45 decalin 1 0.34 1 18 26 45 decalin 1 0.29 1 18 27 45decalin 2.5 0.3 2.5 18 28 45 decalin 1 1.47 1 18

Examples 17, 18, 19, 22, 23 and 24

The metallocene used wasisopropylene(1-indenyl)(3-t-butylcyclopenta-dienyl)zirconium dichloride.

Examples 20, 21, 25, 26, 27 and 28

The metallocene used wasisopropylene(1-indenyl)(3-i-propylcyclopenta-dienyl)zirconiumdichloride.

TABLE 11 Yield T_(g) VN Activity Example [g] [° C.] [ml/g] [g/(mmol h)]G_(p)′[Pa] 17 22 84.5 93.7 161,000 678,000 18 49 46.5 63.8 239,000700,000 19 20 90.8 97.7 58,500 648,000 20 29.5 147.6 121.1 157,000363,000 21 35 97.8 75.6 307,000 582,000 22 50.9 131.9 1O1.8 37,200529,000 23 26 95.8 97.1 71,300 549,000 24 65 89.5 71.0 42,500 514,000 2516 110.5 116.7 20,000 515,000 26 29 109.2 77.2 42,400 542,000 27 33.299.8 90.4 47,000 557,000 28 65.3 105.7 95.6 18,900 534,000

Examples 29 to 32

A 50% strength by weight solution of norbornene in toluene was placed ina 70 dm³ autoclave which had previously been purged thoroughly withethene. The solution was saturated with ethene by multiplepressurization with ethene. A methylaluminoxane solution in toluene (10%strength by weight methylaluminoxane solution having a molar mass of1300 g/mol according to cryoscopic determination) was metered incountercurrent into the reactor which had been prepared in this way andthe mixture was stirred for 30 minutes at 70° C. A solution of themetallocene in a methylaluminoxane solution in toluene was added afterpreactivation for 30 minutes.

While stirring (750 rpm), polymerization was carried out for one hour,with the ethene pressure being maintained by metering in furtheramounts.

After the end of the reaction time, the polymerization mixture wasdrained into a vessel and immediately introduced into 300 dm³ ofacetone, stirred for 30 minutes and the precipitated product wassubsequently filtered off. The filter cake was washed alternately withthree portions each of 10% hydrochloric acid and acetone, the residuewas slurried in acetone and filtered off again. The polymer which hadbeen purified in this way was dried at 80° C. under reduced pressure(0.2 bar) for 15 hours.

This gave a colorless polymer. The further reaction conditions and thecharacteristic data of the polymer are summarized in Tables 12 and 13.

TABLE 12 Methyl- Amount Methylaluminoxane Ethene aluminoxane metallocenesolution for pressure Example solution [ml] [mg] metallocene [ml] [bar]29 50 60 250 20 30 50 30 300 20 31 50 15 150 20 32 50 15 125 20

Examples 29 and 32

The metallocene used wasisopropylene(1-indenyl)(3-t-butylcyclopenta-dienyl)zirconium dichloride.

Examples 30 and 31

The metallocene used wasisopropylene(1-indenyl)(3-i-propylcyclopenta-dienyl)zirconiumdichloride.

TABLE 13 Ex- T_(g) VN Elongation at Yield stress Ethene ample [° C.][ml/g] break [%] [MPa] pressure [bar] 29 80 83 >92 56 20 30 92 74 58 6020 31 96 80 33 63 20 32 86 84 50 57 20

Comparative Examples 16 to 25

600 cm³ of a solution of norbomene in toluene are placed in a 1.5 dm³autoclave which has previously been purged thoroughly with ethene. Thesolution was saturated with ethene by multiple pressurization withethene. 5 ml of methylaluminoxane solution in toluene (10% strength byweight methylaluminoxane solution having a molar mass of 1300 g/molaccording to cryoscopic determination) was metered in countercurrentinto the reactor which had been prepared in this way and the mixture wasstirred for 30 minutes at 70° C. A solution of the metallocene in 5 mlof methylaluminoxane solution in toluene was added after preactivationfor 15 minutes.

While stirring (750 rpm), polymerization was carried out for one hour,with the ethene pressure being maintained by metering in furtheramounts.

After the end of the reaction time, the polymerization mixture wasdrained into a vessel and immediately introduced into 5 dm³ of acetone,stirred for 10 minutes and the precipitated product was subsequentlyfiltered off. The filter cake was washed alternately with three portionseach of 10% hydrochloric acid and acetone, the residue was slurried inacetone and filtered off again. The polymer which had been purified inthis way was dried at 80° C. under reduced pressure (0.2 bar) for 15hours.

This gave a colorless polymer. The further reaction conditions and thecharacteristic data of the polymer are summarized in Tables 14 and 15.

TABLE 14 Monomer Amount E- solution of thene [% by metall- press-Comparative weight of ocene ure example norbornene] Metallocene [mg][bar] 16 85 isopropylene(1-indenyl)- 1.5 6 cyclopentadienylzirconiumdichloride 17 85 dimethylsilylbis(1-indenyl)- 10 6 zirconium dichloride18 85 diphenytmethytene(9- 2.7 6 fluorenyl)cyctopentadienyl zirconiumdichloride 19 85 isopropylene(4,5-benzo-1- 1 6indenyl)cyclopentadienylzi rconium dichloride 20 85dimethytsilyl(4,5-benzo-1- 1 6 indenyl)cyctopentadienylzi rconiumdichloride 21 50 isopropytene(1-indenyl)- 1 18 cyclopentadienylzirconiumdichloride 22 50 isopropylenebis(1- 1 18 indenyl)zirconium dichloride 2350 isopropylenebis(1- 1 18 indenyl)zirconium dichloride 24 50isopropylenebis(1- 1 18 indenyl)zirconium dichloride 25 50isopropylenebis(1- 1 12 indenyl)zirconium dichloride

TABLE 15 Comparative T_(g) VN Elongation at Yield stress example [° C.][ml/g] break [%] [MPa] 16 197 67 3.60 — 17 127 123 3.58 — 18 160 1723.36 — 19 180 96 3.55 — 20 224 56 3.30 — 21 89 41 2.9 22 78 99 5.1 62 2380 121 8.3 61 24 78 89 8.2 31 25 109 115 4.2 —

Comparative Examples 26 to 30

600 cm³ of a solution of norbornene in toluene are placed in a 1.5 dm³autoclave which has previously been purged thoroughly with ethene. Thesolution was saturated with ethene by multiple pressurization withethene. 5 ml of methylaluminoxane solution in toluene (10% strength byweight methylaluminoxane solution having a molar mass of 1300 g/molaccording to cryoscopic determination) were metered in countercurrentinto the reactor which had been prepared in this way and the mixture wasstirred for 30 minutes at 70° C. In some cases, hydrogen was metered inat this point to regulate the molar mass. A solution of the metallocenein 5 ml of methylaluminoxane solution in toluene was added afterpreactivation for 15 minutes.

While stirring (750 rpm), polymerization was carried out for one hour,with the ethene pressure being maintained by metering in furtheramounts.

After the end of the reaction time, the polymerization mixture wasdrained into a vessel and immediately introduced into 5 dm³ of acetone,stirred for 10 minutes and the precipitated product was subsequently,filtered off. The filter cake was washed alternately with three portionseach of 10% hydrochloric acid and acetone, the residue was slurried inacetone and filtered off again. The polymer which had been purified inthis way was dried at 80° C. under reduced pressure (0.2 bar) for 15hours.

This gave a colorless polymer. The further reaction conditions and thecharacteristic data of the polymer are summarized in Tables 16 and 17.

TABLE 16 Comp- ara- Monomer Amount of Amount tive solution [% metalloceEthene of ex- by weight of ne pressure hydrogen ample norbornene]Metallocene [mg] [bar] [mmol] 26 10 isopropylene- 0.11 16 1.6bis(1-indenyl)- zirconium dichloride 27 20 isopropylene- 0.28 14 1.6bis(1-indenyl)- zirconium dichloride 28 30 isopropylene- 0.24 14 1.6bis(1-indenyl)- zirconium dichloride 29 50 isopropylene- 0.45 12 —(1-indenyl)- cyclopenta- dienyl- zirconium dichloride 30 50isopropylene- 1.03 3 — (4-indenyl)- cyclopenta- dienyl- zirconiumdichloride

TABLE 17 Comparative Yield T_(g) VN Activity A* example [g] [° C.][ml/g] [g/(mmol h)] G_(p)′[Pa] 26 18.9 12.7 94.4 58,000 880,000 27 21.843.5 93.3 34,000 610,000 28 26.7 74 85.2 19,000 510,000 29 55.6 122 6536,000 330,000 30 33.6 181 81 12,500 200,000

What is claimed is:
 1. A process for preparing a cycloolefin copolymerwhich comprises polymerized units of which from 0.1 to 99.9% by weight,based on the total amount of monomers, are derived from at least onepolycyclic olefin of the formula IV, V, V′, VI, VII, VIII or IX

where R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵ and R¹⁶ are identical ordifferent and are each a hydrogen atom or a hydrocarbon radical, whereidentically numbered radicals in the various formulae can have differentmeanings, from 0 to 99.9% by weight, based on the total amount ofmonomers, are derived from at least one monocyclic olefin of the formulaX

wherein q is from 2 to 10, and from 0.1 to 99.9% by weight, based on thetotal amount of monomers, are derived from at least one acyclic 1-olefinof the formula XI

wherein R¹⁷, R¹⁸, R¹⁹ and R²⁰ are identical or different and are each ahydrogen atom or a hydrocarbon radical, which comprises polymerizing inthe presence of a catalyst system comprising at least one cocatalyst andat least one metallocene wherein said at least one metallocene is of theformula II

wherein M¹ is titanium, zirconium or hafnium, R¹ is an indenyl group ora 4,5,6,7-tetrahydroindenyl group which is substituted in positions 2and 3 exclusively by hydrogen atoms and in positions 4, 5, 6 and 7 maycontain further substituents in place of hydrogen, R^(1′) is acyclopentadienyl group which is substituted in position 3 by aC₂-C₄₀-group which is optionally halogenated, SiR⁴ ₃, NR⁴ ₂, SiR(OR⁴)₃,Si(SR⁴)₃ or PR⁴ ₂, where R⁴ are identical or different and are each ahalogen atom, a C₁-C₁₀-alkyl group or a C₆-C₁₀-aryl group or form a ringsystem, and in the further positions 2, 4 and 5 may bear furthersubstituents, R² is a single-, two- or three-membered bridge which linksR¹ and R^(1′) in each case via position 1 and is

wherein R⁵ are identical or different and are each a hydrogen atom, aC₁-C₄₀-group which is optionally halogenated, wherein O=1, 2 or 3, M² issilicon, R³ are identical or different and are each a hydrogen atom, aC₁-C₄₀-group, an OH group, a halogen atom or NR⁷ ₂, where R⁷ is ahalogen atom, a C₁-C₁₀-alkyl group or a C₆-C₁₀-aryl group, or R³together with the atoms connecting them form a ring system, where n=2.2. The process as claimed in claim 1, wherein the metallocene is acompound of the formula II

where M¹ is titanium, zirconium or hafnium, R¹ is an indenyl group or a4,5,6,7-tetrahydroindenyl group which is substituted in positions 2 and3 exclusively by hydrogen atoms and in positions 4, 5, 6 and 7 may bearfurther substituents such as one or more halogen atoms and/or one ormore C₁-C₁₀-groups in place of hydrogen, R^(1′) is a cyclopentadienylgroup which is substituted in position 3 by a C₂-C₄₀-group such as aC₂-C₁₀-alkyl group which may be halogenated, a C₆-C₂₀-aryl group whichmay be halogenated, a C₆-C₂₀-aryloxy group, a C₂-C₁₂-alkenyl group, aC₇-C₄₀-arylalkyl group, a C₇-C₄₀-alkylaryl group, a C₈-C₄₀-arylalkenylgroup, SiR⁴ ₃, NR⁴ ₂, SiR(OR⁴)₃, Si(SR⁴)₃ or PR⁴ ₂, where R⁴ areidentical or different and are each a halogen atom, a C₁-C₁₀-alkyl groupor a C₆-C₁₀-aryl group or form a ring system, and in the furtherpositions 2, 4 and 5 may bear further substituents such as one or moreC₁-C₁₀-groups or one or more halogen atoms in place of hydrogen, R² is asingle-, two- or three-membered bridge which links R¹ and R^(1′) in eachcase via position 1 and is preferably

where R⁵ are identical or different and are each a hydrogen atom, aC₁-C₄₀-group such as a C₁-C₁₀-alkyl group which may be halogenated, aC₆-C₂₀-aryl group which may be halogenated, a C₆-C₂₀-aryloxy group, aC₂-C₁₂-alkenyl group, a C₇-C₄₀-arylalkyl group, a C₇-C₄₀-alkylaryl groupor a C₈-C₄₀-arylalkenyl group, where O=1, 2 or 3, M² is silicon, R³ areidentical or different and are each a hydrogen atom, a C₁-C₄₀-group suchas a C₁-C₁₀-alkyl group, a C₁-C₁₀-alkoxy group, a C₆-C₁₀-aryl group, aC₆-C₂₅-aryloxy group, a C₂-C₁₀-alkenyl group, a C₇-C₄₀-arylalkyl groupor a C₇-C₄₀-arylalkenyl group, an OH group, a halogen atom or NR⁷ ₂,where R⁷ is a halogen atom, a C₁-C₁₀-alkyl group or a C₆-C₁₀-aryl group,or R³ together with the atoms connecting them form a ring system, wheren=2.
 3. The process as claimed in one or more of claims 1 to 2, whereinthe metallocene is a compound of the formula II in which M¹ iszirconium, R¹ is an indenyl group which bears no substituents in placeof the hydrogen atoms, R^(1′) is a cyclopentadienyl group which issubstituted in position 3 by a C₂-C₁₀-alkyl group such as ethyl, propyl,isopropyl, tert-butyl or n-butyl, by a C₆-C₂₀-aryl group, aC₇-C₁₀-arylalkyl group, a C₇-C₄₀-alkylaryl group, SiR⁴ ₃, NR⁴ ₂,Si(OR⁴)₃, Si(SR⁴)₃ or PR⁴ ₂, where R⁴ are identical or different and areeach a halogen atom, a C₁-C₄₀-alkyl group or a C₆-C₁₀-aryl group or forma ring system, and in the further positions 2, 4 and 5 bears nosubstituents in place of the hydrogen atoms, R² is a single-, two- orthree-membered bridge which links R¹ and R^(1′) in each case viaposition 1 and is preferably

where R⁵ are identical or different and are each a hydrogen atom, aC₁-C₄₀-group such as a C₁-C₁₀-alkyl group which may be halogenated, aC₆-C₂₀-aryl group which may be halogenated, a C₆-C₂₀-aryloxy group, aC₂-C₁₂-alkenyl group, a C₇-C₄₀-arylalkyl group, a C₇-C₄₀-alkylaryl groupor a C₈-C₄₀-arylalkenyl group, where O=1, 2 or 3, M² is silicon, R³ areidentical or different and are each a hydrogen atom, a C₁-C₄₀-group suchas a C₁-C₁₀-alkyl group, a C₁-C₁₀-alkoxy group, a C₆-C₁₀-aryl group, aC₆-C₂₅-aryloxy group, a C₂-C₁₀-alkenyl group, a C₇-C₄₀-arylalkyl groupor a C₇-C₄₀-arylalkenyl group, an OH group, a halogen atom or NR⁷ ₂,where R⁷ is a halogen atom, a C₁-C₁₀-alkyl group or a C₆-C₁₀-aryl group,or R³ together with the atoms connecting them form a ring system, wheren=2.
 4. The process as claimed in claim 1, wherein the metallocene isselected from the group consisting of:isopropylene(1-indenyl)(3-isopropylcyclopentadienyl)zirconiumdichloride,diphenylmethylene(1-indenyl)(3-isopropylcyclopentadienyl)zirconiumdichloride,methylphenylmethylene(1-indenyl)(3-isopropylcyclopentadienyl)zirconiumdichloride,isopropylene(1-indenyl)(3-t-butylcyclopentadienyl)zirconium dichloride,diphenylmethylene(1-indenyl)(3-t-butylcyclopentadienyl)zirconiumdichloride,methylphenylmethylene(1-indenyl)(3-t-butylcyclopentadienyl)zirconiumdichloride,isopropylene(1-indenyl)(3-trimethylsilylcyclopentadienyl)zirconiumdichloride,diphenylmethylene(1-indenyl)(3-trimethylsilylcyclopentadienyl)zirconiumdichloride,methylphenylmethylene(1-indenyl)(3-trimethylsilylcyclopentadienyl)zirconiumdichloride,isopropylene(4,5,6,7-tetrahydro-1-indenyl)(3-isopropylcyclopentadienyl)zirconiumdichloride,diphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(3-isopropylcyclopentadienyl)zirconiumdichloride,methylphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(3-isopropylcyclopentadienyl)zirconiumdichloride,isopropylene(4,5,6,7-tetrahydro-1-indenyl)(3-t-butylcyclopentadienyl)zirconiumdichloride,diphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(3-t-butylcyclopentadienyl)zirconiumdichloride andmethylphenylmethylene(4,5,6,7-tetrahydro-1-indenyl)(3-t-butylcyclopentadienyl)zirconiumdichloride.
 5. The process as claimed in claim 1, wherein themetallocene is selected form the group consisting ofisopropylene(1-indenyl)(3-t-butylcyclopentadienyl)zirconium dichloride,diphenylmethylene(1-indenyl)(3-t-butylcyclopentadienyl)zirconiumdichloride,methylphenylmethylene(1-indenyl)(3-t-butylcyclopentadienyl)zirconiumdichloride, isopropyl(1-indenyl)(3-isopropylcyclopentadienyl)zirconiumdichloride, diphenylmethylene(1-indenyl)(3-isopropylcyclopentadienyl)zirconium dichloride andmethylphenylmethylene(1-indenyl)(3-isopropylcyclopentadienyl)zirconiumdichloride.6. The process as claimed in claim 5, wherein the cocatalyst used is analuminoxane.
 7. The process as claimed in claim 1, wherein a temperatureof from −78 to 150° C. and a pressure of from 0.01 to 64 bar areemployed.
 8. The process as claimed in claim 6, wherein a temperature offrom 0 to 100° C. and a pressure of from 0.01 to 64 bar are employed. 9.The process as claimed in claim 1, wherein the polymerization is carriedout in the liquid cycloolefin itself or in cycloolefin solution.
 10. Acycloolefin copolymer obtained by the process as claimed in claim
 1. 11.The cycloolefin copolymer as claimed in claim 10, which comprisespolymerized units of which from 0.1 to 99.9% by weight based on thetotal amount of monomers, are derived from at least one polycyclicolefin of the formula IV, V, V′, VI, VII, VIII or IX

where R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵ and R¹⁶ are identical ordifferent and are each a hydrogen atom or a hydrocarbon radical, whereidentically numbered radicals in the various formulae can have differentmeanings, from 0 to 99.9% by weight, based on the total amount ofmonomers, are derived from at least one monocyclic olefin of the formulaX

wherein q is from 2 to 10, and from 0.1 to 99.9% by weight, based on thetotal amount of monomers, are derived from at least one acyclic 1-olefinof the formula XI

wherein R¹⁷, R¹⁸, R¹⁹ and R²⁰ are identical or different and are each ahydrogen atom or a hydrocarbon radical, wherein the polymerization tothe cycloolefin copolymer proceeds with retention of the rings and thecycloolefin copolymer has a plateau modulus G′_(p) which corresponds tothe formula log G′ _(p)≧−0.0035T _(g)+6.
 12. A cycloolefin copolymer asclaimed in claim 11 wherein said modulus G′_(p) corresponds to theformula log G′ _(p)≧−0.0035T _(g)+6.03.
 13. A cycloolefin copolymer asclaimed in claim 11 wherein said modulus G′_(p) corresponds to theformula log G′ _(p)≧−0.0035T _(g)+6.06.
 14. The cycloolefin copolymer asclaimed in claim 10, which comprises polymerized units of which from 0.1to 99.9% by weight, based on the total amount of monomers, are derivedfrom at least one polycyclic olefin of the formula IV, V, V′, VI, VII,VIII or IX

where R⁹, R¹⁰, R¹¹, R¹², R¹³, R⁴, R¹⁵ and R¹⁶ are identical or differentand are each a hydrogen atom or a hydrocarbon radical, where identicallynumbered radicals in the various formulae can have different meanings,from 0 to 99.9% by weight, based on the total amount of monomers, arederived from at least one monocyclic olefin of the formula

wherein q is from 2 to 10, and from 0.1 to 99.9% by weight, based on thetotal amount of monomers, are derived from at least one acyclic 1-olefinof the formula XI

wherein R¹⁷, R¹⁸, R¹⁹ and R²⁰ are identical or different and are each ahydrogen atom or a hydrocarbon radical, wherein the polymerization tothe cycloolefin copolymer proceeds with retention of the rings and thecycloolefin copolymer has an elongation at break R which corresponds tothe formula R≧−0.0375 T_(g)+12.
 15. A cycloolefin copolymer as claimedin claim 14, wherein R≧−0.0375T _(g)+17.
 16. A cycloolefin polymer asclaimed in claim 14, wherein R≧−0.0375T _(g)+22.
 17. A cycloolefincopolymer as claimed in claim 11 wherein the polycyclic olefin is acompound of the formula IV or VI in which R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴,R¹⁵ and R¹⁶ are identical or different and are each a hydrogen atom or ahydrocarbon radical where identically numbered radicals in the variousformulae can have different meanings.
 18. A cycloolefin copolymer asclaimed in claim 11, wherein the polycyclic olefin is norbornene ortetracyclododecane.
 19. A cycloolefin copolymer as claimed in claim 18,wherein the acyclic 1-olefin is ethylene.
 20. A molding comprising atleast one cycloolefin copolymer as claimed in claim
 11. 21. A polymerblend comprising at least one cycloolefin copolymer as claimed in claim10.
 22. The molding as claimed in claim 20, wherein the molding is afilm, sheet, hose, pipe, rod, fiber or injection-molded part.
 23. Theprocess as claimed in claim 1, wherein the metallocene is a compound ofthe formula II in which M¹ is zirconium, R¹ is an indenyt group whichbears no substituents in place of the hydrogen atoms, R^(1′) is acyclopentadienyl group which is substituted in position 3 by aC₂-C₁₀-alkyl group, a C₆-C₂₀-aryl group, a C₇-C₁₀-arylalkyl group, aC₇-C₄₀-alkylaryl group, a SiR⁴ ₃, NR⁴ ₂, Si(OR⁴)₃, Si(SR⁴)₃ or PR⁴ ₂,where R⁴ are identical or different and each a halogen atom, a C₁-C₄₀-alkyl group or a C₆-C₁₀-aryl group or form a ring system, and inthe further positions 2, 4 and 5 bears no substituents in place of thehydrogen atoms, R² is a single-, two- or three-membered bridge whichlinks R¹ and R^(1′) in each case via position 1 and is

where R⁵ are identical or different and are each a hydrogen atom, aC₁-C₄₀-group which may be halogenated, and where O=1, 2 or 3, M² issilicon, R³ are identical or different and are each a hydrogen atom, aC₁-C₄₀-group, an OH group, a halogen atom or NR⁷ ₂, where R⁷ is ahalogen atom, a C₁-C₁₀-alkyl group or a C₆-C₁₀-aryl group or R³ togetherwith the atoms connecting them form a ring system, where n=2.
 24. Theprocess as claimed in claim 1, wherein R^(1′) is a C₂-C₁₀-alkyl groupwhich is optionally halogenated, a C₆-C₂₀-aryl group which is optionallyhalogenated, a C₆-C₂₀-aryloxy group, a C₂-C₁₂-alkenyl group, aC₇-C₄₀-arylalkyl group, a C₇-C₄₀-alkylaryl group a C₈-C₄₀-arylalkenylgroup.
 25. The process as claimed in claim 1, wherein the catalystsystem consists essentially of at least one cocatalyst and at least onemetallocene.